Huginn: A Peltier-based sub-cryostat for neutron scattering

A longstanding problem in facility based experiments is the time one must wait whilst changing sample temperature. This issue is most often confronted at cryogenic temperatures above 100 K, where thermal response times can be very slow. These can be drastically reduced by minimising the amount of material being controlled to as little as possible beyond the sample itself. Peltier elements provide an effective way to achieve this, but are mostly used to regulate with respect to room temperature. We report on the Huginn sub-cryostat, a cryostat insert with dual Peltier regulation, useable down to 100 K, that enables large and rapid temperature jumps of up of 10 K to 20 K in minutes or less. Moreover, temperature stability is improved by an order of magnitude in the presence of a variable background temperature.